Hypertension

• Blood pressure is very important to kidney health. Your kidneys use blood pressure as a tool to filter the impurities from your blood. They also help maintain healthy blood pressure by releasing hormones. Hypertension, or high blood pressure, is a big red flag when it comes to kidney damage. That is because hypertension can both be caused by weak kidneys or lead to weak kidneys in an otherwise healthy person. In many cases, hypertension is the first and only sign of weak kidneys.
  
  

Uremia

• Uremia is the high concentration of urea in the blood. Urea is a waste produced when proteins are broken down. Normally, your kidneys will remove urea from the blood stream and use it to make urine, excreting it from the body. When your kidneys are weak, they may not be able to filter enough urea out of the blood and the urea begins to build up. Urea is toxic, and excess urea can cause your brain and heart to shut down.
  
  

Fluid Retention

• Another sign of weak kidneys is fluid retention. Also called edema, fluid retention is the buildup of fluid in abnormal areas of the body, like your extremities. Strong, healthy kidneys remove excess water from the blood and use it to make urine. When the water is not removed, it finds other places to go, like your ankles or your fingers. In some case, weak kidneys can even cause edema in the face.
  
  

Anemia

• Anemia means there is a low presence of oxygen in your blood. Oxygen is required by every cell in your body for even the most basic functioning abilities. Red blood cells transport oxygen to all parts of your body using the circulation system. Healthy kidneys release hormones that trigger the production of red blood cells. Weak kidneys do not release enough or any of that hormone, causing a low red blood cell count. The resulting anemia can make you feel uncharacteristically weak or tired.
  
  

Hematuria

• Hematuria is the presence of blood in urine. Weak kidneys have trouble filtering the impurities and excess water from the blood while allowing the proteins and nutrients to remain. If your kidneys are weak, blood can pass through the filtration system, mixing with the urine. In fact, any changes in your urine can be a sign of weak kidneys. That includes dark, cloudy or even particularly smelly urine.